6. To count how many times user tony" is logged in, then type at the ($) prompt the command: a. who tony | grep | WC-C b. who l grep tony wc-1 c. we | who | grep tony d. grep tony | wc-1 *. it in your current working directory have only the files (chil ch.2.2, ch3.a, ch4.4. ch5.5, ch6.6, ch7.7), then typing at the (S) prompt the command "se?(4501 T will display: a. eh 1.l. ch2.2, ch3 3, ch77 b. chl.1, ch2.2, ch3.3 e. ch4.4. ch5.5, ch6.6 d ch4.4 ch.5 ch.6, ch 7.7 8. if in your current working director have only the files teh 1.1, ch2.2. ch3.3 ch. ch.b. ch6.6. ch77. then tuning at the (5) prompt the commands 7.67 templ: cat templ" will displays a.ch6.6. ch 7.7 b. chl.i, ch2.2, ch3.3, ch4.4. ch5,5 c ch 1.1. ch2.2, ch3.3, ch4.4, ch5,5 d. ch7.7 9. The shell prompt($) is stored in the shell variable named: a. PATH b. PSI C. PATHFINDER d. PS2 10. Comprised of the set of tracks described by all heads on separate platters at a single seek position: a track b. disk c. cylinder d. sector